Symptoms of my phantosmia have largely disappeared. They do occasionally appear suddenly however. Everything would smell normal then I would smell cigarette smoke where there shouldn’t be any, like at a non-smoker’s house. This happened to me Thursday night. I can’t remember the last time I had symptoms but after dinner at a friend’s house, suddenly I was flooded with the smell of cigarette smoke. Again, I think it’s sinus related. During dinner, I was hot and sweating a bit so I took off my jacket. Then it became too cold and I was getting a few chills. I noticed when the temperature is cold outside and I go walking, it would sometimes make the phantosmia symptoms appear. The symptoms are rare enough now that I think it’s safe to assume I’m not getting a brain tumor.